If, like my Bandit, the stock headlight wiring on your bike leaves a bit to be desired you will not get all the light you can from the bulbs. I installed one of their kits in my Bandit and the increase in light output was astounding. This is due to the fact that a small drop in voltage to the bulb results in a big decease in light output.

I can't find the light right now, but a chart I came across on Hella's site showed a 15% drop in voltage resulted in close to a 40% drop in light output..

Using my Bandit as an example, after the kit install I can see almost as far down road with the low beam as I could before with the high beam.